After more reading I learned the center hole on the SBC 1961 LCF Wrecker bell housing is bigger than my aluminum 3858403 sbc bell housing and has caused problems for a Saginaw. I'm back to looking for a 153 tooth flywheel that will fit inside the aluminum one.I'm cleaning up my Saginaw in the ba*****t with degreaser and any solvent I can find cheap. Someone painted orange right over the crud.How do I get the metal to look clean? I see others with nice clean cases.Are they sandblasting them? I don't have that option. This is my recording, songwriting and part cleaning station.Family members were complaining about the smell,so I used my old cig smoking fan down there.I quit cigs 3 years ago in the name of parts buying..I thought I was not up to carrying transmissions down stairs, but I guess not.lol I quit recording about the same time.I'm back though and better than ever!http://www.youtube.com/user/rightfuzzball is me. I do now know that the 153 tooth/ 12 and 3/4 width flywheel with 10.4 clutch is correct for the smaller 3858403 bell housing.I was considering going with my 1961 cast 3925505 Bell housing that I have the 163 tooth flywheel and clutch for. But now I am certain I will need to buy the smaller flywheel to make this Saginaw work correctly. I also learned the 2 bolt starter is what I will need, The 3 bolt diagonal is for the 163 tooth flywheel or flexplate I looked and my 1971 Impala 350 block has 3 holes but I'm told the two will still line up.But must use the support brace that goes with the starter and correct starter bolts.Not just any bolts.The 1961 bell came with the starter that mounts on the Bell housing.It's a really thick flywheel, very heavy.
If you want to use your '61 cast iron bell housing/flywheel/starter combo, I've seen adapter rings sold on Ebay that reduce the 5 1/8 inch center holes down to the smaller size.
Or get a transmission front bearing retainer from a truck saginaw 3 speed. Paint stripper, oven cleaner, laquer thinner will all remove paint. Some cost more or less, some are messier and more toxic, none of them are pleasant. there are 168, not 163 teeth on the big 14" diameter flywheel.